Filter Design by Impulse Invariance Digital Signal Processing--IIR Digital Filter Design He=月.o-7立.(+m 2o+2 21 (s+o1)2+2 -o1±j21 e sin T 1-2z-ea!cos T+2e-2iT 上浒充通大￥Digital Signal Processing—— IIR Digital Filter Design Filter Design by Impulse Invariance ( )       = ∑ + ∞ =−∞ T m H j j T H e a m j π ω ω 1 2 ( ) ∑ ∞ =−∞ =       = = + m z e m T H s j T H z ST H s 1 2π ( ) ˆ a a 1 1 1 1 2 2 1 1 1 1 1 1 1 2 2 1 , ( ) sin 1 2 cos T T T j s ze T ze T ze σ σ σ σ σ − − − − Ω − ±Ω + +Ω Ω − Ω+